Black Hole
by reminiscent-afterthought
Summary: [AU] In which Yugi is a Shinigami, Seto is a Quincy and Noa is an Arrancar out for revenge.


**A/N:** Written for the Yugioh Fanfiction Contest, Season 12, Round 1: Stepshipping (Mokuba/Noa). Also written for dear Milly through the GGE who was one of the people who encouraged me to watch Bleach in the first place and let me bug her with complicated questions and who requested any Yugioh pairing except Thiefshipping. *hands fic and lovebuckets to Milly*

* * *

'_Brother? Why do you have to kill them? Why can't you let the Shinigami purify them?'_

'_Shinigami are deaf and soft-hearted fools. I don't plan on losing you waiting for them to finish their little rituals.'_

**.**

**Black Hole**

**.**

Whenever his brother left in white, Mokuba knew it meant there was another Hollow close by. And Mokuba knew to stay at home and safe so he wouldn't distract his brother. If he didn't, and he had followed his brother a few times before he'd known better, Seto would be too distracted to fight at his best, and he'd come home with wounds littering both body and pride. And, in a way, Mobuka didn't want to follow Seto anymore; Seto was ruthlessness at its worst, firing spirit particle arrows with the intent to kill and never suffering the consequences. Dressed in the Quincy's white battle outfit like that and standing, back straight and arrow drawn straight to the whole that replaced the hollow's heart with nothing save focus in those cold brown eyes –Mokuba could barely see his kind and loving big brother under the warrior's guise.

So he stayed at home and watched the black cloud on the sky grow, waiting for it to wane and then disappear as his brother killed yet another corrupted soul. He still somewhat wished it was different, that they could be saved like the Shinigami claimed they could. But those claims meant nothing when a new Hollow appeared in their town without a Shinigami chasing it. Because then it was a decision between killing a hollow or watching it devour human souls.

If only the Shinigami would work with the Quincy, Mokuba thought, then we really could save those souls… But it wasn't happening, and Mokuba knew his brother was doing the best he could.

**.**

Seto despised both the Hollow and the Shinigami; the Hollow for their sheer brutality and the Shinigami for their laziness – because if the world really was in eternal balance the number of apt Shinigami should perfectly cover the space of the world and prevent the Hollow from wreaking havoc on human civilisation. Instead, spiritually aware humans who should get a reprieve from those other realms in life and become Shinigami in the afterlife, were forced to take up arms against the depraved dead.

He didn't particularly revel such fights, but he didn't plan to let a single Hollow near his little brother. So whenever he sensed that crushing feeling in the air and saw the black cloud appear in the sky and spread like black ink in stagnant water, he adorned his battle costume and armaments and disappeared into the streets after the Hollow that would appear, cutting it off from his life, his home and the remains of his family.

He'd be damned if Mokuba saw a Hollow again.

**.**

Sometimes, the cloud was quick to disperse. At other times they lingered, and Mokuba knew his brother would come back tireder and more grouchy than usual. In the worst case – that hadn't happened yet as far as he recalled – would be him coming back with blood following his tattered form. Milder injuries were more common, particularly to the wrist, forefinger and elbow where the strain of constantly firing arrows sat in.

That was the person that his classmates often saw, because he'd be missing school while his injuries healed and someone would drop off his homework for him. Mokuba used to try to catch them at the door instead, but Seto also tended to be overprotective when injured.

Especially when it was Yugi who knocked on the door.

Mokuba didn't mind Yugi too much as a person; he was awfully serious for someone with such colourful hair (except the moments where he was more childlike and far more friendly, but that was more the Gikon), but he was a Shinigami, and because of his ineptitude, Seto was constantly fighting. Yugi never tried to defend himself against the accusation, maybe because no-one said it to his face. But that strain was there, and Mokuba had to wonder why he'd constantly volunteer to bring homework over for Seto.

Mercifully, that wasn't often, but it was often enough for Mokuba to wish his brother didn't have to get hurt so much. If only he had Quincy power himself – but he had procured no spirit particle yet from his surroundings. Detecting reiatsu seemed to be the limit of his Quincy heritage, and while Seto was happy to keep it that way, Mokuba found himself feeling powerless and sad every time a Hollow emerged.

If they didn't hurt his brother so often, he would wish more firmly they could be saved. But when he came home with a bleeding hand, Mokuba could only be grateful that Seto had come home at all.

Their parents hadn't.

**.**

He was leaving in white again, seconds after they both felt a massive force of reiatsu emerge. Mokuba kept vigil by the window as he always did, searching for the cloud that told its location. He found it, near the school and quite a distance away, but pulsing dark. The reiatsu was so strong as well, stronger than he'd ever felt before.

He was scared: for Seto…and for himself as well. Even though there was no reason to be scared, safe inside his home.

**.**

The cloud in the sky stayed dark. Worse, it moved, coming closer despite the wind blowing east, away from their home.

It was still miles from his home when the window shattered. Mokuba shrieked as he covered his ears, then again as he noticed a shadow in white over him.

'Ni-san, you – ' he began, thinking it was Seto in his battle attire, but then he saw the face and height and knew it was someone else. Someone who looked more like Seto's little brother than Mokuba himself, but could not possibly so.

And then there was half of a Hollow mask on his face. The reiatsu still felt distant though.

When the other grabbed him though, it felt strong, like a hundred needles puncturing into his skin. The reiatsu was different though, completely different to the one he could still feel, miles away and tangling with his brothers.

**.**

There had been two Hollows. He hadn't detected the other's reiatsu immediately though; he'd felt the Menos and he'd been pushed back by it. So when he felt that other, stronger reiatsu, it was like something had stabbed into his chest.

And then the trace vanished as quickly as it had come, and he was struggling against the Menos with an added worry in his mind.

Because that flux of reiatsu had been too close to his home for comfort. He couldn't do a thing though, because a Menos was far more powerful than a regular Hollow, and as much as he loathed to admit it, he was getting steadily pushed back.

**.**

Yugi came. Yugi the Shinigami, wielding his shikai: Burakku Majishan. Seto, worried about his brother and too spent to refuse help against an enemy he couldn't defeat, agreed to fight together. And they did, piercing the hole that represented the absence of the Hollow's heart.

The moment he saw the giant form begin to disintegrate, Seto ran for his house. He was careless – he would realise it later, and the purple eyes following his back just in case – but his mind, now free from fighting the Menos, was focused on just one thing: Mokuba.

**.**

Mokuba struggled against the paralysis that held him. His kidnapper had used some sort of spell – he thought it might be kido, but the reiatsu he had felt was more akin to a Hollow than a Shinigami – and there was that half-mask as well.

'I'm an Arrancar,' the kidnapper said, pre-empting the question as he appeared in Mokuba's line of vision again. 'My name is Noa.'

**.**

Seto found the living room window shattered and the lingering traces of strong reiatsu. Yugi appeared but moments later, having followed once he'd confirmed the Menos' destruction. Seto started at his presence; he'd been so focused on getting home he hadn't noticed.

'I don't sense your brother's reiatsu here,' Yugi said with a frown as he surveyed the living room area. 'Can you?'

Seto glared; he didn't like the other's self-assured tone, but he had to admit to himself he hadn't even looked for his brother's reiatsu yet. When he did though, he could only detect the lingering traces that had engraved themselves into their home. There was no trail leading away; it vanished along with the other one.

'Arrancar,' the Shinigami said after a moment of examining the reiatsu, before snapping up when it looked like Seto was about to run back into the streets. 'Don't be foolish; an Arrancar is far too powerful for you to handle on your own.'

Seto was usually reasonable, but he lost reason when things concerned the well-being of his brother and so he didn't listen. Yugi looked at him leave, tracing the reiatsu all the while as he called Soul Society. He wasn't fool enough to believe he could handle an Arrancar without backup – or at least a release on his limiter.

**.**

**.**

Noa was silent after his introduction, but not unkind. He kept Mokuba paralysed but did nothing else. He had even seated the other comfortably, instead of leaving him splayed on the floor as he could so easily have done. Now, he was just staring out the window. So was Mokuba, because his head was held too high to see anything apart from Noa's half-masked head and aforementioned window.

'Why have you brought me here?' he asked eventually. His mouth tingled, but moved. He could blink as well; it seemed those organs had escaped the paralysis spell – or whatever it was.

Noa turned to him, considering the question. 'You're bait,' he said eventually. 'For Kaiba Seto.'

**.**

Seto searched aimlessly, failing to find even a trace of his brother. Yugi caught up to him soon and stopped him. 'You won't find him like that,' he said. 'Wait for Soul Society to track them.'

'I should wait for the same people who were too slow to save my parents,' Seto snapped back, ready to ignore the Shinigami once again.

'And what do you know about Arrancar?' Yugi counted.

Nothing, though Seto did not say that out loud. Yugi knew anyway, because he continued. 'The abilities of an Arrancar are far beyond Menos. They have acquired a human-like form and Shinigami-like powers. They have even acquired Zanpakutos from Shinigami they have defeated and devoured. And their intelligence and conscience is well beyond that of a Menos; in a sense, they can be considered to be the shadows of Shinigami.' He stroked his own released Zanpakuto. 'Even a Lieutenant like myself will struggle against one with the limiter and without bankai.' He locked eyes with Seto. 'Put your stubbornness aside,' he cautioned. 'This is not the time for us to argue about our clans, with your brother's life in danger.'

He didn't say the alternative and Seto did not think it.

**.**

'Why Ni-san?' Mokuba asked.

Noa suddenly appeared much closer, and much more menacing. 'He's _my_ brother,' he spat venomously. 'My perfect younger brother who stole everything from me.'

Mokuba's mind froze in shock and the Arrancar's mouth twisted into a menacing smirk. 'I've come for my revenge on him,' he said. 'A revenge I've waited _years_ for, that I _became_ this Arrancar and devoured countless Shinigami and Hollow for.'

Mokuba said nothing after that, but Noa seemed angry still, his pacing taking on a new ferocity and reiatsu leaking out like sparks from a livewire.

**.**

Soul Society took a bit to find the Arrancar, but they managed it and Yugi was quick to lead Seto there. The Arrancar welcomed them too, having waited for their approach.

He gave Yugi an indifferent look before his lips twisted into a smirk at the sight of Seto. 'I've been waiting,' he said, waving a hand in the air. 'And I've got a little present for you too.'

Part of the air separated itself from the normal plane and showed the inside of an abandoned building and a sprawled form on its floor.

Seto fired an arrow before quite registering that his little brother was captive to the Arrancar.

'Now, now,' the Arrancar clicked at him, blocking the strike with one palm. 'You wouldn't want anything to happen to this little boy, would you?'

He looked sideways at Yugi again, who loosened his hold on his Zanpakatou.

**.**

'What do you want?' Seto gritted his teeth. Yugi had been right; the Arrancar was highly intelligent to take a hostage, and his brother of all people to boot. It was almost as though he'd been targeted specifically, for all the spiritually strong people in Domino City. 'Let my brother go.'

The Arrancar's gleeful expression twisted into one of horror. 'Funny how you care about what happens to him,' he spat, 'when you destroyed me.'

'Don't mess with me,' Seto snapped. 'I don't know you, and the only person I care about is my brother.'

'_I_ am your brother,' the Arrancar screamed, before releasing a burst of green light Seto barely managed to dodge. 'And you killed me! You took my place as Mum and Dad's favourite, their little heir! It's your fault I ended up this way!' Each statement was punctured with another release of green light, and Seto found it more difficult to dodge each time. Perhaps it was the sheer ferocity, or perhaps it was the fight with the Menos catching up with him. Or maybe it was just the inability to fight, because the Arrancar still had Mokuba.

'I don't know what you're talking about,' Seto said, breathing heavily and shaking from the accumulations of little wounds and over-exertion as the Arrancar paused in his assault. 'I only ever had one brother, and my parents were killed by a Hollow years ago.'

'I killed them!' the Arrancar snapped, and Seto froze. Yugi, find an opening through the exchange, shifted his Zanpakuto straight into its Bankai state and struck. It connected solidly with the wrist of the hand through which he'd been firing his green shots, and severed it cleanly.

'Bastard,' the Arrancar spat, turning his attention away from Seto. 'You could have survived if you hadn't interfered.'

There was no blood from the wound, only the empty stump and the Arrancar didn't seem bothered by it at all, simply using his other hand to fire his shots.

Seto stared at them for a moment, before running into the building behind the Arrancar, looking for his brother.

**.**

Seto found Mokuba easily enough, but when he shook the other, he did not respond. That's when he noticed the chain snaking out on the floor – back outside.

'You noticed.' The Arrancar suddenly appeared inside. 'Here's here; with me.' And indeed the Arrancar did have a firm grip on the other end of the chain, the chain still attached to the chest of Mokuba's soul. Mokuba who currently had his eyes shut and head slightly lolled forward, as if asleep.

'Mokuba!' Seto cried, allowing worry to exuberate his tone. And Mokuba stirred, blinking blearily before seeing his brother's beaten body.

'Ni-san!' he screamed, before crying in pain as Noa tightened his grip.

Seto noticed the severed hand was rejuvenating, looking skeletal but useable. And it must have been, because it held onto a pulse of green light with its fingertips. 'Not another step,' the Arrancer said, showing the light, 'or I'll fire my Cero through his chest and sever the chain.'

Seto gritted his teeth. Maybe he could sacrifice another human; maybe he couldn't. But Mokuba was the one thing in the world he couldn't lose. The Arrancar knew that too, because there was gloating in his eyes as he added: 'Stay still like a good little boy and deal with your punishment.'

And he fired his Cero bolts, low powered, and watched as they battered Seto one by one and dropped him to the ground.

**.**

Mokuba watched his brother get beaten down, watched as Cero after Cero pelted into him and brought him to his knees. Watched as he struggled not to fight back, in case _he_, Mokuba, got hurt. Not fight because Mokuba was the one thing Seto couldn't bear to lose.

'Stop!' Mokuba screamed finally, tears streaming down his face. 'Noa, please stop!'

Seto struggled to look up as the Arrancar, Noa, held back his bolt with a shaking hand. Then he gritted his teeth. 'No,' he said, 'I waited too long for my revenge!' The green energy grew stronger and his reiatsu became crushing, overwhelmingly strong.

'Revenge won't get you anything!' Mokuba screamed. 'Did you feel better when you killed our parents?' He didn't remember his parents, not like Seto. It hurt to say, but he could say it.

Noa lowered his hand a tad, before raising it again. 'He's the one at fault!' He pointed at Seto with the energy that he'd collected in his fingertips. 'I won't rest until I've killed him!'

'And what about me?' Tears still streamed down Mokuba's face. 'If Seto's your brother, I'm your brother too. And I don't want either of my brothers to be hurt any more.'

**.**

Mokuba had stopped Noa. He'd called him his brother too. He'd said he cared. No-one had cared about Noa, not since his parents had tossed his spiritually inadept body aside when Seto showed his first signs of Quincy powers. Not when he'd been run over by a car and died. Not when he'd wondered the world, watching Seto grow into his Quincy heritage, a heritage that had escaped Noa.

He had never seen Mokuba. He'd become a Hollow before that. And Mokuba had never heard of him. But he'd still called him a brother.

Part of him thought it could be a hoax that Mokuba could just be trying to save his brother. But most of him was filled with something else: an emotion he couldn't recall. And, suddenly, his mind was clear from hatred and the thought of vengeance. And the Cero at his fingertips disappeared as, before him, Seto struggled to his knees.

But then the overwhelming feeling struck: the feeling that he'd felt when he'd first become a Hollow. The feeling of hatred and pain and anger and jealousy all crushing him, swallowing him whole. He roared, roared so his scream echoed to be heard for miles by anyone who was spiritually aware, and that forced Mokuba's soul to curl in pain, and Seto and the approaching Yugi to wince in pain.

He wanted to kill again, but Mokuba calling him a brother still echoed and he didn't want to kill.

He released Mokuba, and the soul fell, getting tangled in the long chain that still connected it to the body.

Maybe…maybe the problem was that he'd been too self-centred. Too lonely. He could have had brothers. Real brothers that loved him, and he loved them. Instead, jealousy, and later hatred, had devoured him.

'Kill me,' he whispered, barely audible as that warm feeling struggled fruitlessly to push back the hate. 'Quick; kill me.'

Seto summoned an arrow, but this time, it was to him Mokuba screamed to stop. His pleading gaze made Seto let go of his weapon once more and grit his teeth. The Arrancar before him spasmed in the air, muttering unintelligibly.

'Let me,' Yugi said, raising his Zanpakatou.

Seto looked at Mokuba again, who nodded hopefully. Seto jerked his head in allowance. Yugi nodded at him, then struck with his sword, and all of them saw the full smile of Noa as the mask broke.

The rest of him disappeared soon after, to the Soul Society.

**.**

'Did you find out about Noa?' Mokuba asked, weeks later.

'Yeah,' Seto muttered, but didn't elaborate.

Mokuba was persistent though. 'What did you find out?'

Seto sighed. 'Nothing much.'

Mokuba was disappointed, but he stuck to the topic. 'Were you worried about what he said?'

'No,' was the short reply.

Mokuba knew that meant "yes".

'You let Yugi send him to Soul Society.'

'Who could resist those eyes of yours?' Seto rubbed his temples. 'This was an exception though; unless that Yugi does his job properly, I'm going to continue doing things my way.' But there wasn't as much bite in the tone. Maybe, working together as they'd been forced to had let Seto to accept Shinigami, or Yugi at least, just a little more.

And the business with Noa had perhaps softened Seto to Hollows just a little more as well. Enough to pity them a tad, for how they'd allowed their hatred, from whatever root, to devour them.

**.**

**.**

**Post A/N:** Since I know some people fandom blind for Bleach will be reading this, explanations!

Hollow: they're born from human souls that don't cross over into the Soul Society after death and become corrupted (by anger, pain, desire for revenge, fear etc.). These hollows lose their human memories and become monsters that feed off souls: human and Shinigami. If a Shinigami cuts them with their Zanpakuto, they will be purified and enter the Soul Society after destruction. They are sometimes born on earth, but there is also a dimension for them (not really relevant here). Physically, Hollows have white creepy looking masks, black bodies and a hole where their heart should be. Hollows have a lot of levels: regular Hollows are the weakest of them. Arrancar are far stronger, and they have enough power to gain a human-looking form (though they still have a part of their mask) and Shinigami-like powers as well. You usually need bankai level powers to defeat them. Menos are the level before Arrancar, where they're way bigger than usual Hollows but haven't achieved the ability to take on human-like forms yet. To advance through these stages, Hollow devour other Hollows. Some reach their limits; others evolve. Appearances of Hollows from their dimension is usually accompanied by a black cloud like thing in the sky, which appears when they return or are destroyed/purified. Some Hollows have memories of their time as humans (or parts of them anyway), so for this I have Noa remember his jealousy for Seto. Also, with Arrancar,

Cero: an attack that some of the arrancar use. It's a green light laser sort of thing.

Soul Society: sort of like the afterlife. It exists parallel to the human world and is where pure souls go after death. People who die in the Soul Society are usually resurrected on earth again without memories of their past life.

Shinigami: soul reapers. Their task is to keep the balance of souls in earth and Soul Society equal (since someone who dies on earth is supposed to go to Soul Society, and someone who dies in Soul Society goes to earth etc.) Some are stationed in highly spirit dense places on earth where Hollows are known to appear. Their main weapon is a custom Zanpakuto, but they can also use Kido spells (spells which use their spiritual power). Shinigami come from Soul Society; they are people who enter Soul Society with high spiritual power and undergo training to become a Shingami. There is an academy for that, and certain thresholds. Once they graduate, they are assigned a squad and become full fledged Shinigami. They have certain rankings in the squad as well, starting from captain, then lieutenant (lieutenants and captains have a limiter on their power when they come to earth, which can be removed by special request in emergency situations), then seated officers. Shinigami are usually only visible to people with strong spiritual powers, unless in a Gigai. Their uniforms are black. The only reason Yugi's not captain level is because it's unusual for a captain to be stationed in earth for a long period of time; usually they're only temporarily stationed when there's some sort of immediate problem that needs resolving. Lieutenants can be though.

Zanpakuto: the main weapon of the Shinigami, which usually (there are a few exceptions) appears as a reguar sword unless "released". There are two released forms: shikai and bankai. Bankai is the one that mostly only captains can use (and a good many exceptions in the anime :D) since it requires a lot of training and spiritual energy. Shikai is the more common one, but also not as strong as bankai. In front of stronger enemies, bankai becomes necessary. In both cases, the shape of the sword changes; bankai is usually far more extravagant than shikai. Yugi's shikai is the phonetic of the Japanese name for Dark Magician; his bankai is Majishan Obu Burakku Kaosu, ie. Magician of Black Chaos.

Gigai: the temporary vessel a Shinigam inhabits while in the human world so they can be visible to humans and integrate into society. Its appearance reflects the normal appearance of the shinigami. They exist the gigai while fighting spiritual forces.

Gikon: an artificial soul a Shinigami can put into their gigai, otherwise it would drop unconscious which can cause a little panic. :D The gikon come with personalities of their own. For this fic, Atem is the shinigami; Yugi is the gikon personality, but they're both referred to as Yugi here (since Atem doesn't need to stand out in Japan and the gikons don't have names usually).

Reiatsu: projection of spiritual power. Most people with strong spiritual power can sense reiatsu; it's the way Shinigami and Quincy can know when there's a Hollow or another strong spiritual energy nearby.

Quincy: these people are said to be the opposite of the Shinigami. They are alive, for one, and exist on earth and not the soul society. They manipulate spiritual particles into a bow and arrow, their main weapon. Like Shinigami, they fight against hollows, however their arrows don't have the purifying ability that Shinigami Zanpakuto do, so Shinigami think they disrupt the balance. The two clans are at war, and a lot of the Quincy have been exterminated by the Shinigami as a result, and most of the remaining Quincy have a deep hatred for Shinigami. This is coupled with the fact that, while Shinigami monitor the Quincy, they do not assist them when they're attacked usually. Quincy also have the ability to detect reiatsu and see Shinigami. Quincy uniforms are white.

The Chain: this is the chain of life. When the soul ifs together with the body, it is invisible. When the soul is disconnected from the body but is still able to return, the chain appears, linking the hearts of the body and the soul. This soul can be restored by a Shinigami. When the chain is broken though or not present, the spirit can't return to their previous body and have no choice but to be sent to the Soul Society, the process of which is called a "Soul Burial".


End file.
